Planar workpieces whose effective operation requires that they be housed in a tight-fitting receptacle can be difficult to install in, manipulate in, or remove from such a receptacle. Various fields of endeavor utilize or can utilize such planar workpieces including but not limited to technology component or subsystem hardware, medicine, the residential and commercial building trades, and manufacturing or industrial machinery. These planar workpieces could include, for example, boards bearing electronic components, medical or surgical objects or components, filter elements, and machinery components or subsystems.
One such application of a planar workpiece in a tight receptacle is the filter utilized in a commercial or residential forced air heating, ventilating, and air conditioning (HVAC) system. In this case the filter is an example of a planar workpiece and the slot holding the filter is an example of a tight-fitting receptacle. These replaceable filters remove particulate objects from recirculated air during operation. These filters are removed, discarded or cleaned, and then replaced on a regular basis because they become clogged with particulate matter. Such a filter is installed in a slot or receptacle that by design: 1) has little or no space or gap between the filter and the slot, 2) is sized so that when the filter is fully installed the filter top is recessed below or level with the receptacle frame edge and the frame outer edges and filter outer edges overlap, 1) and 2) together helping to ensure that all recirculated air containing particles to be removed must pass through the filter and not around it through any gaps at the edges of the filter. This placement of the filter (planar workpiece) such that its top is recessed below or level with the receptacle frame edge represents the proper operational location for such a planar workpiece.
These filters are planar in shape, typically square or rectangular, and vary in size from a minimum of about 9 by 9 inches to over 25 by 25 inches. One commonly used type of HVAC filter is 1 inch thick. HVAC filters are often manufactured of cardboard or another semi-rigid material for a frame and of filtration materials including but not limited to fiberglass, paper, foam, polyester, cloth, etc.
While in use HVAC filters often become deformed due to the pressure of air passing through them. This deformation process may be hastened if a filter is not replaced after it becomes clogged.
The slot or receptacle that holds an HVAC filter is an integral part of an air handling system comprising ducts typically fabricated from sheet metal at the point holding the filter. These slots are typically installed manually by an HVAC technician during the HVAC system installation process. The result is variation in the precise width, depth and thickness of slots that are ostensibly the same size. In other words some slots designed for a 20×20×1 inch filter will be a tight fit along the edges for a filter of that size, others will be just right, while others will fit loosely. In addition, since the depth of the slot may vary, a filter may drop to the bottom of the filter slot and be below the outer edge of the air handling duct of which the slot is a part, making access for the purpose of filter removal difficult.
As a result, the installation and/or removal of HVAC filters can be difficult for one or more of the following reasons:                a. The fit between filter and filter slot may be tight, making it difficult to push the filter into the slot on installation and pull the filter from the slot on removal.        b. The outer edge of the filter may, when fully installed in the slot, be below the outer edge of the duct containing the filter slot, making it impossible to access the edges of the filter with human fingers during the removal process.        c. The filter may have become deformed during use, making it impossible to access the edges of the filter with human fingers during the removal process and/or difficult to remove due to the deformation.        d. The gap between the edges of the filter and the edges of the filter slot may be too small to permit human fingers or a tool such as pliers to grasp the filter during the removal process.        e. The space above and/or around the filter slot through which a filter being installed or removed must pass may be difficult to access with human hands due to its location or may be partially obstructed by system components such as air ducts and/or gas or electrical lines.        
The same difficulties discussed above for the HVAC filter example apply to other applications that utilize planar workpieces in tight-fitting slots.